1. Field of the Invention
The present invention relates to a system for monitoring and controlling one or more track networks to effect the safe and efficient movement of one or more railway vehicles on a plurality of track sections of the one or more track circuits.
2. Description of the Related Art
A prior art system for controlling the movement of one or more railway vehicles or trains on a track circuit typically includes a number of discreet elements distributed along the track circuit for sensing and controlling the position of track switches and for sensing and controlling the movement of trains. These sensing and control elements include, without limitation, switch machines coupled to track switches for monitoring and controlling the position thereof, vehicle presence detectors for detecting the presence of trains on sections of the track circuit and traffic lights. These sensing and control elements are well-known in the art and, therefore, will not be described in detail herein.
In a prior art system for controlling the movement of one or more trains on the track network, the sensing and control elements are connected to a central office which includes appropriate electrical and electronic computer controlled hardware operating under the control of a software program to acquire the output of the sensing elements; to process the output of the sensing elements as a function of a desired movement of one or more trains on the track network; and to control the control elements to effect the safe and efficient movement of the one or more trains on the track network.
A problem with the prior art systems for controlling the movement of one or more trains on a track network is that the central office is often located more than 1,000 feet away from the sensing and control elements associated with the track circuit. To this end, it has been observed that an average distance between the central office and the sensing and control elements is on the order of 1,500 feet. Because the central office is connected directly to each sensing and control element, a cable having a large number of wires, e.g., stranded and/or solid wires, must be connected between the central office and the sensing and control elements. Moreover, this cable must include wires of different gauges for conveying sensing signals, which can be conveyed over a smaller diameter wire, and for conveying control or energizing signals, which must be conveyed over larger diameter wires. Because of the possible number of wires included in a cable and the length of the cable, these cables can be expensive to prepare and install. In addition, because of the wide variations of sensing and control elements that may be needed for different track circuits, it is not practical or cost effective to build cables having a standard number of wires and/or a standard length in a manufacturing environment, where such cables could, if standardized, be manufactured both practically and cost effectively.
It is, therefore, an object of the present invention to overcome the above problems and others by providing a distributed control system for monitoring and controlling the sensing elements and controlling control elements associated with a track network. Still other objects will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description.
Accordingly, I have invented a system for controlling the movement of one or more vehicles or trains on a track network. The system includes a plurality of switch machines, with each switch machine outputting a switch position signal indicative of the state of a track switch associated with the switch machine in one of a plurality of positions, and receiving a switch control signal related to a desired state of the track switch in one of the plurality of positions. A local controller is connected to receive from each switch machine its switch position signal and to output a first communication signal including switch position data corresponding to the switch position signal output by at least one switch machine. The local controller also receives a second communication signal including switch control data corresponding to a desired state of at least one track switch, and outputs to the switch machine associated with the at least one track switch, as a function of the switch control data, the switch control signal. Lastly, a central office is connected to receive the first communication signal and to output the second communication signal as a function of the first communication signal and the desired movement of one or more vehicles on the track network.
At least one traffic light can be connected to the local controller. The traffic light can have a plurality of states, and the second communication signal can also include traffic light control data corresponding to a desired state of the traffic light. The local controller can output to the traffic light, as a function of the traffic light control data, a traffic light control signal related to the desired state of the traffic light.
At least one vehicle presence detector can be connected to the local controller. The vehicle presence detector can output to the local controller a vehicle presence signal corresponding to the presence of a vehicle on the track network. The first communication signal can include vehicle presence data corresponding to the vehicle presence signal output by the vehicle presence detector.
Preferably, at least one of the first communication signal and the second communication signal is a network protocol communication signal. The local controller is preferably positioned closer to the plurality of switch machines than the central office.
The local controller can include a first programmable controller and a second programmable controller connected for at least one of (i) operation redundant mode of operation where each of the first and second programmable controller compares the switch position signal from each switch machine, outputs the first communication signal, receives the second communication signal, and compares the switch control data; and (ii) a fail-safe redundant mode of operation where the first and second programmable controllers coact to output the switch control signal which comprises a pair of voltages which cause the switch machine to switch the track circuit to a desired state.
I have also invented a distributed control system for a track network. The distributed control system includes a local controller connected to a plurality of switch machines and a central office. Each switch machine is configured to monitor and control the state of at least one track switch associated therewith. The central office is configured to control the movement of vehicles on the track network. The local controller is configured to receive from each switch machine a switch position signal and to output to at least one switch machine a switch control signal related to a desired state of the track switch associated with at least one switch machine in one of a plurality of positions. The local controller is further configured to output to the central office a first communication signal including switch position data corresponding to the switch position signal output by the at least one switch machine and to receive from the central office as a function of the first communication signal and a desired movement of one or more vehicles on the track network a second communication signal which includes switch control data corresponding to the switch control signal output to the at least one switch machine.
Preferably, at least one vehicle presence detector is connected to the local controller. The vehicle presence detector is configured to output to the local controller a vehicle presence signal related to the presence of a vehicle on the track network. The first communication signal can include vehicle presence data related to the vehicle presence signal output by the vehicle presence detector. At least one traffic light can also be connected to the local controller. The local controller can control the traffic light to be in one of a plurality of states in response to the traffic light receiving from the local controller a traffic light control signal related to the one state. The second communication signal can include traffic light control data corresponding to a desired state of the traffic light and the local controller can output to the traffic light, as a function of the traffic light control data, the traffic light control signal. The plurality of optical states of the traffic light can include an on-state and an offstate of one lamp.
Each switch machine is connected to the local controller by a first cable, and the central office is connected to the local controller by a second cable. The maximum length of the first cable is less than the maximum length of the second cable.
I have also invented a method of controlling vehicles on a track network. The method includes providing a track network having a plurality of switch machines connected to a local controller. The local controller receives from each of the switch machines a switch position signal related to a state of a track switch associated with the corresponding switch machine. At least one switch position signal received by the local controller is converted into switch position data which is transmitted from the local controller to a central office. Switch control data is received by the local controller from the central office as a function of the switch position data transmitted to the central office and a desired movement of vehicles on the track network. The switch control data received at the local controller is converted into a switch control signal which is conveyed from the local controller to the at least one switch machine which sets the corresponding track switch to a state related to the switch control signal.
The local controller can also receive from a vehicle presence detector a vehicle presence signal related to the presence of a vehicle on the track network. The vehicle presence signal received by the local controller can be converted into vehicle presence data which can be transmitted from the local controller to the central office. The switch control data received at the local controller from the central office can also be a function of the vehicle presence data.
Traffic light control data can also be received at the local controller from the central office as a function of the switch position data and a desired movement of vehicles on the track network. The traffic light control data corresponds to a desired state of a traffic light connected to the local controller. The traffic light control data received by the local controller can be converted into a traffic light control signal which is transmitted from the local controller to the traffic light whereby the traffic light is set in one of a plurality of optical states.
Lastly, I have invented an apparatus for controlling vehicles on a track network. The apparatus includes a central office configured to control the movement of vehicles on the track network and a plurality of switch machines. Each switch machine is configured to output a switch position signal indicative of a state of a track switch associated with the switch machine in one of a plurality of positions and to control the state of the track switch in response to receiving a switch control signal. A local controller is configured for receiving from the plurality of switch machines the switch position signals related to the state of the track switches controlled by the plurality of switch machines. The local controller converts the switch position signals into switch position data and transmits the switch position data to the central office. The local controller receives switch control data from the central office as a function of the transmitted switch position data and a desired movement of vehicles on the track network. The local controller converts the received switch control data into switch control signals and conveys each switch control signal to one of the switch machines whereby the corresponding track switch is set to a state related to the switch control signal received by the one of the switch machines.
A traffic light can be connected to the local controller and the local controller can receive traffic light control data from the central office as a function of the switch position data and a desired movement of vehicles on the track network. The local controller converts the received traffic light control data into a traffic light control signal and transmits the traffic light control signal to the traffic light whereby the traffic light is set in one of a plurality of optical states as a function of the traffic light control signal.
Lastly, a vehicle presence detector can be configured to output to the local controller a vehicle presence signal as a function of the presence of a vehicle on the track network. The local controller converts the received vehicle presence signal into vehicle presence data and transmits the vehicle presence data to the central office. The switch control data received by the local controller can also be a function of the transmitted vehicle presence data.